1. Field of the Invention
The present invention relates generally to communication systems and, in particular, to a method and apparatus for providing localized information to communication devices operating in a wide area communication system.
2. Description of the Related Art
Wide area communication systems, such as paging systems, cellular telephone systems, and two-way radio systems, are well known. Such systems provide communication service to large numbers of communication devices distributed throughout a wide geographic area. To provide communication service to the communication devices, wide area systems typically include, inter alia, control and routing equipment, such as system controllers, base site controllers, paging controllers, routers, switches, and other known devices, and base or broadcast transmission sites that provide information to and receive information from the communication devices over wireless resources or channels. The geographic areas of wide area systems are typically subdivided into smaller regions referred to as xe2x80x9ccoverage areas,xe2x80x9d with each coverage area being serviced by one or more broadcast transmission sites depending on system traffic density and other system design considerations.
In wide area systems, messages and/or other information are delivered to communication devices based on the type of system and the system protocol. In most systems, each communication device includes an individual address or identification (ID). Thus, when information is intended for one communication device only, the information is transmitted together with the individual address of the communication device. For example, in a one-way paging system, after receiving a request to page a particular communication device, the communication device""s individual address (e.g., pager number), and a desired message intended for the communication device, the paging controller sends the communication device""s individual address and the desired message to all broadcast transmission sites in the system. At the appropriate time, in accordance with the paging protocol of the system, the broadcast sites simultaneously transmit (i.e., simulcast) the desired message and the individual address in their respective coverage areas, effectively transmitting the message throughout the entire system. Simulcasting in this manner insures that the target communication device receives the message regardless of which coverage area the device is currently located in.
In other systems, the communication devices can include an individual address and a group or broadcast address to enable the devices to receive messages intended for their respective groups as well as messages intended for them individually. One such use of a broadcast address is to provide information to communication device users that subscribe to a national news service. For example, in a paging system that provides paging service throughout the entire United States (typically referred to as a nationwide paging system), paging customers can also subscribe to a news service that couples into the paging system. The news service provides its subscribers with periodic updates (short text messages) regarding information of national importance, such as stock updates, technology updates, and national news. The news service could send the updates to each subscriber individually using the individual address of the subscriber""s communication device. However, such individual messaging to large numbers of devices would be an inefficient use of system resources. Therefore, the communication device of each service subscriber is typically programmed with a broadcast address associated with the particular service. When a news service update is received at the nationwide paging system controller, the paging system either sends the update to the broadcast transmission sites for simulcasting (e.g., when the update includes the corresponding broadcast address) or prepends the appropriate broadcast address to the update and then sends the broadcast address/update combination to the broadcast transmission sites. At the appropriate time, in accordance with the paging protocol, the broadcast transmission sites transmit the update and broadcast address throughout the system, thereby providing the update to all the subscribing communication devices simultaneously and efficiently.
Although the above-described nationwide news service broadcasts are efficient for conveying information of national importance, such broadcasts are not very efficient for conveying localized information. For example, nationwide broadcasting of local traffic information for Miami, Fla. is not an efficient use of the resources at broadcast sites in, for example, Los Angeles, Calif. because news service subscribers in Los Angeles are not likely interested in the traffic conditions in Miami. For that matter, news service subscribers in Jacksonville, Fla. are not likely interested in the traffic conditions in Miami either.
Therefore, a need exists for a method and apparatus for providing localized information to communication devices operating in a wide area communication system that efficiently utilizes system resources to convey the localized information.